The construction of a conventional nuclear magnetic resonance probe coil comprising superconductive thin film is discussed in the patent literature 1 (Japanese Patent Laid-Open No. H11(1999)-133127). The invention relates to a so-called birdcage-type probe coil, and the direction of the static magnetic field and the directions of insertion and drawing out of a sample are parallel.
To make a high-resolution, high-sensitivity NMR apparatus, it is effective to apply a strong static magnetic field to a sample or use a high-sensitivity probe coil. To generate an uniform, strong magnetic field, it is desirable to make the diameter of the coil to produce the magnetic field small and it is necessary to make small the space occupied by the probe coil disposed in the coil. The probe coil forms a resonance circuit. To make a high-sensitivity probe coil, it is effective to raise the quality factor of the probe coil. To achieve a high quality factor, it is necessary to reduce the resistance in the probe coil.
A trial to make a probe coil of superconductive thin film is discussed in the Japanese Patent Laid-Open No. H11(1999)-133127. As the direct-current resistance of a superconductor is zero and its high-frequency resistance is small, it is useful as a constituent of a probe coil. In this case, the resistance in the resonance circuit is expressed as a sum of the resistance of constituents and that of their connections, and the contribution of the constituent made of superconductive thin film can be ignored. Accordingly, the resistance in a resonance circuit which comprises superconductive thin film is lower than the resistance in a resonance circuit which does not comprise superconductive thin film.
However, although the above prior art relates to a probe coil made of superconductive thin film, it discusses the construction of a so-called birdcage-type probe coil. To make a high-sensitivity probe coil, it is effective to achieve a high quality factor, improve the uniformity of the magnetic field, reduce the space occupied by the probe coil, and use a solenoid-type probe coil, but the above prior art does not discuss the construction of a solenoid-type probe coil.
That is because the birdcage-type probe coil is used in the NMR device wherein the direction of the static magnetic field and the directions of insertion and drawing out of a sample are parallel, whereas the solenoid-type probe coil is used in the NMR device wherein the direction of the static magnetic field and the directions of insertion and drawing out of a sample are orthogonal. Namely, although the former device has been studied very much, the latter device has not been studied very much. As a result, the solenoid-type probe coil has not been studied very much.